Intramedullary fasteners such as Sampson rods and Rush rods are used to stabilize the location of bone fragments so that they may be closely approximated and placed in the proper anatomical position for healing. Particularly in younger patients, such fasteners are usually removed after the bone is fully healed. In other patients, removal may become necessary due to infection or pain caused by the fasteners, or in the event the fasteners become bent or fractured during rehabilitation.
Over a period of time, a fibrous band of bone marrow, tissue, and in some instances cancellous bone, grows around intramedullary fasteners making them difficult to remove. Preferably, the fasteners should be withdrawn from the bone along the axis in which they entered to avoid bending of the fastener and possible fracture of the bone. It is also desirable to avoid rotating the fastener during removal since such twisting motion can result in bending or fracture of the fastener in situ and/or damage to the bone.
Currently, intramedullary fasteners such as Sampson rods and Rush rods are most commonly removed by surgical pliers and other hand tools. In many instances, manual retraction procedures require a substantial amount of manual force and can be very time consuming and physically exhausting to the surgeon. Mechanical devices have been developed for the extraction of intramedullary fasteners, but for various reasons none have been considered an acceptable replacement for hand tools. The extractors disclosed in U.S. Pat. Nos. 2,693,798 and 3,626,935, for example, are relatively complicated in design and uneconomical. A comparatively simpler and cheaper device is described in U.S. Pat. No. 2,631,584, but that extractor causes the intramedullary fastener or rod to rotate as it is being withdrawn and also imposes an axial force directly against the bone and tissue surrounding the surgical fastener. This force can damage the tissue and cause the bone to chip or fracture. A further limitation of these prior extractors is that their fastener engaging ends or hooks are intended for a specific type of rod or nail and may not be interchanged to accommodate different types of fasteners or fasteners of varying sizes.